In a large mixing bowl combine the flour, sugar, baking powder, baking soda, and salt.

Juice the tangerines to make 1 cup of juice.

In a small bowl beat the eggs, add softened butter, and tangerine juice. Mix well.

Add the liquids to the dry ingredients and mix to incorporate.

Mix in zest and diced tangerine.

For the icing - mix the tangerine juice and powdered sugar together. When the cake is completely cooled spread the icing over top. Slice the remaining two tangerines very thin and place on top of cake.